SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbc653c280cf520af4ccf56b4ba39e6eb120480361802d142195f6602665f828' 
  AND token = 'aQCoDJtxWmU1w32LqR+GAxD8HC5syFmmDQZKq1X6wuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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