SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '200075b08accadc9bf111d793b2bee6df92478ac1de8359ae11492cada5ae831' 
  AND token = 'QQAe92HSQorcmYDU0oMJ9I5INKVvy0DITZx8Y9s53k4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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