SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '27e0e817995d00ca1680053fddbaab4281e2a863b8faa0790a05b9d5a04a7909' 
  AND token = 'cJthHWxYZOB4MwU4Kw7OsXwDa85IegQwDwlu9POY2xI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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