SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'add0084a0921a40ba1d3611f67f179e180f69d9a13ea108b04579ba4effa09c8' 
  AND token = 'BkA7zQHlbyWKfrolvXXLtae4EhfE0HKRtQxdHpdhGEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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