SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fa59951db0c583a4d77e57bc8498c05c54fcddac46915d562793fae550628ef' 
  AND token = '7axDFIPmuWNzXWnypsgxh3pLKXitg0Q/SOynVWEsyW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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