SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56a41f519a4cbcee9e7e94a107acc29f3c0448c7d831c751010f07ef1e2d4acf' 
  AND token = 'qX1leoj2pZiuKMjln0J0dlkKp/ENAzTikynpvvwmcqc=' 
  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"
    }
  }
}