SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '931dce383b54e88e6d61edefe85071a222f68b0ae7ad7444ca697fd8d937ed24' 
  AND token = '8p4TSLrjFJ7u3/ztRRiV0ZaOqF3xVj4CtX/BCM6sHUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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