SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e3bb41dd658f4343e89de8dc3f1d8bfffef2a5c119db6a85632c0515f54add9' 
  AND token = '6IBpkMgmm5ujkzyTSnrlbqD0x76Jq0H4lMQgbtGw2eo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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