SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1fdc9bf124bcc194fca96f7e6cb5a50819cdff2b9fbf74b393b9a0e0a6b1d246' 
  AND token = 'LiCkB86mhzrw1T8xpjVwxWJA7QqTEHgoYue9L79BQx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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