SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1831b727465f73a83df759004db50b0998a887ebdeff248191248775584ad7c0' 
  AND token = 'tQMfHrUTPIN4W+1V9XyerSf7F2gK3Tb83WajI4T9Flo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}