SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0c458498d30a7c57b187da8eaed34bf8199b6cfb18556e1ffb5b77c3a2ff19' 
  AND token = '4nRA3UTCsjFKyA0QS7bTiBgyjCxDVoNbytUo9le3x4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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