SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c5f6b9e09f29524cb11f3f06c74367227018abdf109b4cbb17f99a655e1991d' 
  AND token = 'SWjLqKrQ0AT3HDHOfPMyB9xpIF2eqA72CcQbikn8Ftw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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