SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aba77b3719e0cef0bfa28431ba61b4fd2bf3c86c68dac933c7480df8da0fe87' 
  AND token = 'R1ubIiPQv8O3cx7WXios939LyX30pSzsXMjblMA4xso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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