SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6244c53c438c55b10046ee03b5fa7ee57b763c0b2218b47d5c85635f206f09bd' 
  AND token = '0AkcAJ4UTRW7z22fY4dn2kpo7PepKKyPbYBOrTOThFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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