SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '282916677ad7f95ce20abcba742a5aacc63a20a20c7dc36a3ba760b51a15edfb' 
  AND token = 'x9rg242vpCKHETlOgNX5LTtyVO8F9IFq+nFJ1WVT5TI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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