SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e004ddc1ff847d7039b54d3ac2aa528e8d093f765d0d7585a9398f0aa8b9cb0c' 
  AND token = 'uuCboIb9d2Qg6rJiaFJ6CLtnrrgyG/Nzo5pJqEXZefM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}