SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fbd186535625f637e071db968ea8e054e8e21bed350f56a902047ddc5ec4d52' 
  AND token = 'BecncC7gJRMyKn1O8Kst7eTVlcDM3EuAJKglQP8hI5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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