SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3366ccf8e9c4282e171863712cc8181d368ad87be620921e338357c8329ffb94' 
  AND token = 'ZwYLBZAkAJZjZ9TWwTozieBMJONljw8iU7zrOrTjR3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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