SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cf9c55cd34596a52957808ba57df7f81e2f2092ff821e0cfec9c914272fde4ec' 
  AND token = 'LU7WChIze/gW0VXsE99hBUsyGztcJ5ng7PwP+bnUXFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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