SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cb15b122647a4b0da4bf10a33a9a5dcb2605dd6e7b65cb9757d461ce3f9b814' 
  AND token = 'bE+d8vl7jkKT8bYfKJUBHUEm2ZDwpqI6f3psEuj1MgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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