SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c24399857503172a87bdb61c9b0f21fe183fd7c7ee049d5f3adf1b4cde8cc830' 
  AND token = '9eDIY0s/sSDxn1GPSgw/uY5wAWfH74mQNDWqac9IjtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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