SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acf07548571aa71abe9f48d407f783801f813c3a034ce12612c30dde39578c65' 
  AND token = 'bOh2ofggjch6hy5FLWxheDMxrwMgkGVoQ3hBMEh/HeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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