SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fdb8634461756eb8571af005721e1e5bb0c865f9c99508623ca2dc5c653a42e' 
  AND token = 'qTentU7QhEUhNJKN3/AjTbNT4NNKmaZHMgYoCgwut6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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