SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4481570b9a22500ea4076c6c14ba08a59ef5a9afc6b77b928581ee119a78df2' 
  AND token = 'J6uNPLOb0/YMxr3Jd4uvZ5nF63eXzX8+yWGHs3cMcMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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