SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d6c0b0c90f299b9e67d95bd732c93f340addc7999b4c0443060ce8dec831280' 
  AND token = '8HsS8CSHjOV9FCXU1oTu8jYk6dWBmzfGaXU83OuLRTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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