SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f803ef370438d803babcfb1d695e6bf8316a6d0305b1fd441e4bd19e57d9de72' 
  AND token = '6a6zKQWXpK6hkJN0PqGYMewuW39FmkNyeXQ/Twxc5qA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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