SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '824deaea5efb4f68713c42be57d78dd540b4e53736bea9e3f87e7d21c76ae1de' 
  AND token = 'S1aUyfJi4p557URKf3JkgeNaWfOfHhInWsWfASHXGG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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