Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ff67a5d007765b28914cf7d27d0e2d4729550c82d41d2b01e1a730c880cf12' 
  AND token = 'sUvAK+3/SoFJ10BDKzkY9UyR/CpdpZ3UmwdFs3+8Hic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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