Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8547ce8e3bda6efe85a5326592b89a91e6a9035ce7549230f2ec08c0e8dd6dee' 
  AND token = 'gyaRLDsRTVu/aM9EpWWsfmGv7Ha1ZC3M+ZWP4Kxg7oM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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