SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa012700b7d6641db8cc09cbb6169d201068e04c5c73b63d4593d8fd830255e1' 
  AND token = 'LftZTScpUPrL3f7ZRA+fLe2v4pZDJNMXeFEUDJRapLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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