SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48095fc921bc0ffa168f30471b44ad2f94060278e3bffb55473608cae1942b1d' 
  AND token = 'sRzHVQDppkBq5evJP98iMdcVO7NqUqr9QEhV1He1NOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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