SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fbe973b19074d2df21b3a6575c4f507f75205e67e665d2bfc254e63b125c6cc' 
  AND token = 'DB9Y5WtfNvqYF7+Jwyjap+IbUpyyGXcPiGwFzILkBa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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