SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9547441f0484272039535d75cb7ac19558b294b3b4a337df9c0cf8021e4f07f9' 
  AND token = '+vP+z6WJjo0YaHRWbBk4ZuktMI6PNJpJjgu+Sgo0JBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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