SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9c4e8d629322624c0210798ff90191a93c8a30a81bc64562f73c8372058b54b' 
  AND token = 'qJsKwchxdTLwfuXjkgu92R1wbSluGiv5+I9HveSIuTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}