SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b86ff0cf74e01cfaec3b4d9393677024cf7d994d7692f1b03421f6dbe9bee57' 
  AND token = 'qTRlJ4YTQyK1Ra/j3wrZs3PzDLksO2BXdMsBftUQujA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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