SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a14de1f619aa24fd8605beeff93aba357105e8f7af0b6a92866b347de0d48899' 
  AND token = 'Af2St489l1zJVEUxZwhGInSnYQ8FIy7/hpEct0FVvT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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