SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1bb08efeac88f565ae5a58b3e887fdb02a75aee803f71a9bf641a99bc7a4a2b' 
  AND token = 'ETQVB8AcnUttBy+UJCGQRPoFu2WQRiNiqFlAfZCtJeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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