SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '382b2bb7b52fd09891ac04a898e63cc1121d072b4f0b7aa46635047d0791dbfd' 
  AND token = 'li48Jmw2f/PKeJVgqo7bcZ1ihWhe5j3cDSYd5XW1VXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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