SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5645e1c68535276b4fbda0e3179113415de827248e83d7e249c84356b0fb9299' 
  AND token = '80/Wh2Bqj5R/qvKPl/J7QO7H5zZRqTwZb8Kbs1H0M84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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