SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd47fc00d09469dfb832eb7102739ce9defb48a403d0dafaaba48f57375f9feed' 
  AND token = 'f4271i5S4bU1aQhb1kIn46Dru5fkpeXRh7Vq94FAoDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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