SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b11b8ca5b62af9df96e7e96a9a19fbbc4c361ea8c25f362cb5a37c241d4fae68' 
  AND token = '7R6ZJoKThO3G7ztBFCavsAZx3AbIrXhlyYgbPgiZ84U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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