SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c5b34a128e45b58be651529e18266e944cb03b5ea7921eba3519d784bf9eb7' 
  AND token = 'SDU/qNHuOQaWyvrCJoIQnP/3OX0lVhEFuSjJVuwOq5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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