SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '307294485400d4db5148f0632e6448b2fa95fe811bede777318291c028856c4d' 
  AND token = 'pQj0KTxo7zLjFv1OLFUYD+uJyKjP0VwIs0GHZ9RwZPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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