SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd33182771c6c8231539349b6f2d16754836ffbf297a692d93b4f472ec65d3f40' 
  AND token = 'rV5rjg5hO07OOw0WNWzUikwKvZLRTjjxcW/nCbMCVqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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