SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20bc09f53215fb63d9ce44f5c510738a28cd2db96abe37d481e60d0a55c3207d' 
  AND token = '2NbvAl+txPRMuvzOI+kXNieAGQy67ljLCqAoiNbS5jI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00198

JSON explain

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