SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f402f13d6d0c50ff05ced311d884a14fb19cdb422769d06313c16c7218c48ee7' 
  AND token = '7HcESDIGFu0nwEZju/rKh1OgQQswCgWDHVBLzBRgsa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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