SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fdb54749be06231254285104c7eb77f24fe957136499f1386bd57735b7db22f' 
  AND token = 'XcpCr0CJSdKpgu3Yg+QvhYKwx0zrfFH7HXIczrEV8ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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