SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be37a6b3fd4d190718e16a4d15b775240747b1308ba878823ee13c9257a8c7ce' 
  AND token = 'vveSWnvwGLrnzAhLDtu9MgVsb0BNilNJRYIUA6YTMqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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