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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4666cad5c45252a899f5ca6835ce23ee95028058dd9b8b4d26504403f6c37e4' 
  AND token = 'pjBPZd3PlZGTLf7fJ2AD3KLJ1lR7ccRlC151DcHyMqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}