SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f179a659d6730f78b98db49a3b474bda1d414cd76c8cf3e2f75ddc3d453d4eda' 
  AND token = 'R2syLEqIhcWVo5RFHxwP7YhK9sr/W+DrUvJh3YQko/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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