SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1df23f044c565eadcda7765c4003b9bba26693e0d35673dc64f5a161b2d443a7' 
  AND token = 'zmJlb595Z8ZiRV6O8GHuCr+g+KhMjAlvdlUvUv5xZbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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