SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c83f2458a0299404971dbd30f3b2bec14cf3353f92bfc57857090e20b638ea6c' 
  AND token = 'Sh7K7MXNWeIQzwyNxY0lTcBtno3MDdCpyjkZcBkbbN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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