SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b24bd81a97779679dd3ac225036adef74ae1e5dd58f68be533ef1dc685b53b1' 
  AND token = 'yVzVAXogwWarzNxZlKIiVNyLZ+mXVck7fvtxR+UZCTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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