SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77cc05b407dabcfa25e76272dce1195a319e6e71101f1c37368bbe81d105cd84' 
  AND token = 'VKhFLhCTw8GlvVDkb+ZXSrmOgwLIENiFWQQNALBm79g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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