SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e0d019ea572f4672aec19f47239961d9f820548b98f661fe0cc3308c0aadcce' 
  AND token = 'fwxzeovq03ndPMLF4pIJwp0bjjvm7uwBrBdE+QsOnLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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