SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '63b392a84044576f1df901639ea5ebee2ad0ebd33773cfe0a4f55a6c1ecc11b0' 
  AND token = '+k2Nb/2dR0JeRGXIonV93qX3KSq4LUg1I+2bcIyJZOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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