SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f5e36eb118a7bbb91e0538d575ca12fa86890572794008cd0397414cf9515e4' 
  AND token = 'hQe+2q/vI1GJfOGlJTBV7PYqAnjqGBFfjBEjSE+4OUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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