SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54552a88ee5937662242e746c8102c7fb8e7cebc8976125001f25a2487eace2a' 
  AND token = 'aYqEnR62ulLCuN8Z7lf82stgsWDwsgl7a0fMHIwDnPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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