SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a52df2b0bbf0f6e946077b40b5877053c4e69339a54613a1016adfe9bfcf4b8f' 
  AND token = '36WpXy44ZzQe/pekugIYG/wWKPrvE5DK9hA91HULfCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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