SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a3c294c091d569797f705ace3affbd93aed681bf572472bdfa1520491caac935' 
  AND token = '1F/HOK4CznIDnjXkojI2iLIY0oR0uQL2ky/04liQNUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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