SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfc0379fa6f38c87ec99722c17ab2236ba8ea1b6f509b8a36d79d846d5736f34' 
  AND token = 'iTQNM8MfVIh1lbAW8PN5T/vIm9inz7BLjrM7f9rAfXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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