SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47959758293c0d91934c4a39a47642c21a08073fbf2a9de7edd9cfe3eaef3b56' 
  AND token = 'XgKl8oDr3GJKR4KJFXl1xSPZFSTZnvgosb03+jITu9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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