SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e41e544be97dcd63922f999d8358007fcebf63e8171f5f6d887bb2a150e9ab9' 
  AND token = '82xPHJvcI1RT9fK2L+p2LGNFKmZgWPBFPibDI6xqJ68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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