SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7655f046d57ab8b6cb257f95bde240686476218361efb1cfc9045fc9948d6b5c' 
  AND token = 'KXmOBUHuZmk26bBUmQq3YVOC5Vc9F7d4NYbclqGcO4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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