SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '67b9cc4442e525f16b688ce51d8ec6d88b20c4a3c6ca7756741fbb3e36f44625' 
  AND token = 'V7GVoW/9en81zyr+p/ViwCHNp18rH0cA6C8wED/6lnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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