SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16783350d662a5fe26b1315214d3de6fe7ee4b97c6c57f9cfbf918cfd19f9dd0' 
  AND token = 'zybKqYYvN4IWdbwfsLR+ErXG+oBBQAdCjKSbi/AvF0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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