SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48de31b0bb8ad93df58d7483c966f086a908df1d6b2457c6da093c37b5bfdf44' 
  AND token = 'TaVamrzaufWhTrXfXiKXXHhgYwgq8PJFFPOJR02UX0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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