SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8745d47fb3a4bd3d952f0a920954cc7322bff0776ee92504b04c4cea7af30a1d' 
  AND token = 'YuDUH5BDCcNkIkuCtDrW0MCvF5pCKr43qm0MlDnay3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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