SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e193799524f683de4a00f806311b0ff7c483838559167b94f92d066ab1069aa7' 
  AND token = 'WqwaZ5h/P6gnwNN+FiTfDbZmJ/1I5fHgN3nzjGYWFU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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