SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32084c2424316a843763fb5a1129c9f7f1e4842a03af9840a5ecac71f54fa8f' 
  AND token = 'r0i5tTlOJS7Jg/oRteaFQLNxbf5c1b96EpQtqwNwxqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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