SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a74796d98183c4ed4c27cee280af151c994d34ff3657f3348162b117a1e8c6c' 
  AND token = 'iZ9ebL7kc67qKDE8jJBcjqLWkUUHFtTJCZKhKt09+wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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