SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1b73381ab9a767ce99736293a4e4c9aed55153662e94c54f8fae079704a683a' 
  AND token = '+detn9PZLJN6Jh/JN4YCSEU8gKU9W5zAV0Gs/w2YnIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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