SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '783d6476bd59845c917ffdb461d1e9fd3e4806e0ea79a2d1321a6044eab15b49' 
  AND token = '1Z9rvD/EILCwc/GiwHyFYOkjJ2wkpHaNy+5DZal+sG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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