SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a19df7bb199119d4c9456ec68ee11a3b8cf939e452aa77127da5cca23ed5515e' 
  AND token = 'bd5i8uaSa/HEVMMXM4CxIMRqb3JiPnqzoU0JmeDOHV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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