SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1939fe2e1a38f6069cf2337538b66bed3f099614491068812adec70003f8732' 
  AND token = 'fMePn+XJmEpclAhqEwz051MVh7x0KGWg31Z/31EvlV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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