SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90b1ab3c1429fea1cc535d739873af11d2386ef61772c393904d173a10bd9501' 
  AND token = 'sGxWfGC98GJ23ilYh31eSr0fy9oM6w69+Ez7NAdsP00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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