SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c0eef51d26cc88de6463a93e2d9681d2644e1554793c481f93b9a7dd54980f2' 
  AND token = '+yVWL6RmzfQvAu2BJrHfAqCQgBftPbZ7DNH5L7h9TwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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