SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf06d8c72d3fa5fcc1b585ee41584ff0a199738e7ed74454ed6547a6fc2ce785' 
  AND token = 'ChMJeXfjtktBLvCLEcwKjMDYdOeVNRoYxGQqsa2+XBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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