SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55cef2909714bf66fa833ce380a829a04845415c26d3f039c9ed76949c51f150' 
  AND token = 'bZqdy4MhhnwMLIUA/UEQWXVl4aXCZln+Bv2S25UsaeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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