SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09b5288bfd89322b318a78ad4cbf56fcbb4168af524d01a5129ef089a00fc51a' 
  AND token = 'K/z6xBb0Rtr9ntVwIAPIzi291WqFvHlpq4leZXXhwz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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