SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '177e1fa96dec7c1ba0113a2b7649787e04f605b05699ac8164c81826256a2004' 
  AND token = '0y2VHuKR43KJZQBTKfB2TefCLBtT53h93rgmAPvpqPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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