SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7845d9251809a639ddc70245b5f769b33f42380bfb24741470181a0c30ec82b8' 
  AND token = 'Qzpwm1ebu7ZKp+gqGUKkyTSgLkRc8UTt9Htv5sOVnvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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