SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf9fdd57960eebd91a12fd3f7107e71bf24b4faa8afa33e1d361f95e1fd2a225' 
  AND token = 'Gxf6VLInKvYu2zbz4ra3sKdVezHeEHapE1J/J6GnUrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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